Let J be Jasmine age and S the sister's age. Then, we have
[tex]2S-5=J[/tex]this equality means Jasmine is 5 years younger than twice her sister's age. Now, we also know that J=39 years then by substituying this value into the last equality, we have
[tex]2S-5=39[/tex]and now, we can solve this equation for S. First, we must move -5 to the right hand side as 5. It reads
[tex]\begin{gathered} 2S=39+5 \\ 2S=44 \end{gathered}[/tex]and finally, we obtain
[tex]\begin{gathered} S=\frac{44}{2} \\ S=22 \end{gathered}[/tex]therefore, Jasmine's sister has 22 years old.
